Wireless receiving set for compensating disturbances



March 25, 1930.. s. LOEWE l 1,751,588 WIRELESS VRclarlvnm SETFOR'COMPEN'SATING DISTURBANCES Filed 'July 27, 1926 Patented Mar. 25,1930 UNITED 4sriyrizs .PATENT OFFICE v SIEGMUND LOEWE, OF BERLIN,GERMANY, ASSIGNOR TO RADIO. CORPORATION OF AMERICA, A CORIORATION OFDELAWARE WIRELESS RECEIVING SET FOR COMPENSATING DISTURBANCESAppIication led lJuly 27, 1926, Serial No; 125,313, and in GermanyAugust 1, 1925.

This invention relates to wireless receiving sets, and has particularlyfor its object to suppress'the disturbances which are especial- 1ycaused by electrostatic conditions.

By careful investigations I have found that these disturbances may befully suppressed in the following manner:

The receiving aerial is carried in series or parallel connection throughtwo similar rem ceiving sets E1 and E2. These receiving sets may be ofany desired construction, and may, for instance, consist of athree-valve reflex set. One of these sets, for instance E1, is sharplytuned to the wave to be received and enerally so adj usted, that thereception will e as good as possible. The reception will in this casecomprise to a great extent atmospheric and other disturbances, which aremixed with the reception. The second receiving set is sharply tuned to awave, which is not very diil'erent from the wave, to which the other setis adjusted. This second receiving set, being out of tune with respectto the wave to be received, will not be acted upon by the latter. Thedisturbances, however, will be received by said second receiving set inequal strength and phase. If the reception be designated with E and thedisturbances with S, the first receiving set will reproduce in atelephone or loudspeaker the sum of the reception and the disturbances,that is E' plus S, while the second receiving set will solely reproducethe disturbance, that is S. The diiliculty now consists, to solelyreproduce the difference of the t-Wo energies received b the tworeceiving sets that is the quantity (E plus S) HS.

In the accompanying drawing I have represented a wireless receiving setaccord- 40 ing to my invention. Fig. 1 is a wiring diagram showingdiagrammatically the connections of the wireless receiving set accordingto my present invention. Figs. 2 and 3 are wiring diagrams showingconnections for modiiied wireless receiving sets according to myinvention. l

According to the connections shown in Fig. 1 the operation is asfollows:

Instead of the telephone or loudspeaker,

a resistance for alternating current, that is a clioke coil or aresistance having ahigh-reslstance value such as Dl and D2 is insertedinto the circuit of each receiving set. Paralleling these resistances D1and D2 there are arranged metallic Aplates F1, F2 and FB, F 2respectively, said metallic plates representing electrical capacities.Intermediate these capacities, further capacity plates F6 and F1respectively are provided. Between the capacity plates F6 and F7 thecontrolling circuit of a tube amplifier V is inserted, said amplifierbeing for instance arranged to operate in the known capacity-resistanceconnection. In Fig. 1 a double amplifier is shown diagrammatically. Inorder to explain the operation of this device, it is, for instance,assumed, that the lower ends of the resistances D1, and D2, andtherewith also the plates F2 and F4 are grounded. The plates F1 and F 2,therefore, are under the action of potential variations against ground,and more particularly the potential variations of the plate F1 will takeplace according to the sum E plus S, while the plate F3 will solely beunder the'action of potential variations according to the quantity S.The plates F., and F7 now may be adjusted relativelyto the plates F1,F2, F3 and F2 in such a manner, that a complete compensation of thedisturbances will take place. Between the plates F6 and F7 a very highresistance may be inserted in order to avoid constant charges .of thegrid.

The combination may also be carried out in the manner of providing `abridge connection for the tubes, such as is shown in Fig. 2. In thiscase two tubes R1 and R2 having common or separate heating and anodebatteries are connected to a transformer with three windings a, b and c,the coupling between said windings being made'adjustable. The grid oftube R1 is connected to the plate F6 and the grid of tube R2 to theplate F2, said plates F6 and F7 being adjustably arranged withincorresponding capacity plates, as in Fig. 1. The indicator is connectedto the winding b, the cathodes of the tubes R1 and R2 are grounded andconnected to the plates F8 and F7 by means of high leak resistances K.Instead of the indicator, also a multiple valve amplifier may beinserted into the Winding circuit against the disturbances received byb. It is obvious, that in the manner desaid second circuit. scribed, thegrids of thez tubes R1 and R2 will In testimony whereof I have ailixedmy be acted upon by the receiving set E1, accordsignature.

ing to the value e plus s; and by the receiv- SIEGMUND LOEWE.

ing set E2 according to the value of S, and 70 more particularly to anextent, which may be independently regulated by adjusting the plates F1,F2, F3 and F4. One will therefore lo be enabled to cause only thedifference of 75 these two values to act upon the winding b, this beingeifected by the direction in which the windings a and b are wound. Insome cases also the insertion of a coupling transformer having threewindings a, b and c, as 80 indicated in Fig. 3, will give the sameresult; in this case the Winding ais directly connected to the receivingset E1 and the winding c directly to the receiving set E2 and more par'-3 ticularly in such a sense, that the winding b 85 `will be acted uponsolely by the di'erenc'e of the actions of the two receiving sets.

I claim: 1. A wireless receiving system for eliminating disturbancescomprising .two receiving 90 circuits one of said receiving circuitsbeing tuned to the wave to be received, the other of said receivingcircuits being tuned to a wave somewhat diferent from said former wave,

whereby said first circuit will receive said 95 former wave and thedisturbances and said f second circuit only thedisturbances, andconnections for the audio outputs of said circuit for balancingcapacitively the disturbances received by said first circuit against thedis- Y 100 turbances received by said second circuit so as to obtain acombined receiving action of said circuits without said disturbances.

2. A wireless receiving system comprising o two receivers, one of saidreceivers tuned to 105 receive a desired signal and incidentallyreceiving undesired impulses, the other of said receivers being detunedwith reference to said desired 'signal but receiving said undesiredimpulses, an adjustable capacity in each of the 110 audio frequencyoutput circuits of said receivers, an electron emission tube amplifierincluding a rid and filament, a connection from the gri of said amplierto one of said capacities and a connection from the filament 115 of saidamplifier to the other of said capacities whereb solely desired signalimpulses ffects the t ermionic stream of said ampli- 3. A wirelessreceivinI system for elin1i- 120 natin undesirable distur ancescomprising a plura ity of receiving circuits, one of said circuits beingtuned to a desired signal frequency, another of said circuits beingdetuned relative to said desired frequency whereby said 125 rst circuitwill receive said signal and the disturbances and said second circuitonly the disturbances, and grounded means connected to each circuitaudio output to balance capaci- 4 55 tively the disturbances received bysaid irst 130

